JP7337312B1 - X-RAY GENERATOR, X-RAY IMAGING DEVICE, AND X-RAY GENERATOR ADJUSTMENT METHOD - Google Patents

Abstract

The X-ray generator includes an X-ray generator, an X-ray detector that detects X-rays emitted from the X-ray generator, and a control device that controls the X-ray generator. The X-ray generation device includes an electron gun, an X-ray generation tube including a target that receives electron beams emitted from the electron gun and generates X-rays, and a support structure that supports the X-ray generation tube. a deflector that deflects the electron beam, and the support structure supports the X-ray generating tube so as to allow at least the target to rotate while the deflector is fixed. The control device determines whether the target needs to be rotated depending on the usage amount of the X-ray generator and/or a change in the X-rays generated by the X-ray generator. .

Description

The present invention relates to an X-ray generator, an X-ray imaging device, and an adjustment method for the X-ray generator.

A transmission microfocus X-ray tube generates X-rays by irradiating a target with an electron beam. However, such an X-ray tube has a problem that the target tends to deteriorate because heat is generated by irradiating the target with the electron beam.

In Patent Document 1, a magnet portion is arranged around an X-ray generating tube, and by rotating the magnet portion, the irradiation position of the electron beam on the target is changed, thereby extending the life of the X-ray generating tube. is described. However, when the irradiation position of the electron beam on the target is changed by moving the magnet portion as described in Patent Document 1, the radiation position of the X-rays from the X-ray generator, that is, the focal position, changes accordingly. Therefore, it was necessary to align the X-ray detector for detecting the X-rays emitted from the X-ray generator each time the magnet section was moved, that is, the focal position was changed.

Japanese Patent No. 4309176

The present invention provides an advantageous technique for extending target or x-ray tube life without changing focal spot position.

A first aspect of the present invention relates to an X-ray imaging apparatus comprising an X-ray generator, an X-ray detector that detects X-rays emitted from the X-ray generator, and a controller for controlling the X-ray generator. The X-ray generator comprises an X-ray generator tube including an electron gun and a target that receives an electron beam emitted from the electron gun to generate X-rays, a support structure that supports the X-ray generator tube, and the electron beams. and a deflector for deflecting the line. The support structure supports the X-ray generating tube so as to allow at least the target to be rotated while the deflector is fixed. The control device determines whether or not the target needs to be rotated according to the amount of use of the X-ray generator and/or changes in X-rays generated by the X-ray generator. .

A second aspect of the present invention relates to a method of adjusting an X-ray generator, wherein the X-ray generator includes an electron gun and a target that receives electron beams emitted from the electron gun and generates X-rays. A ray generating tube, a support structure for supporting the X-ray generating tube, and a deflector for deflecting the electron beam are provided. The method of adjusting the X-ray generator is such that at least the above-mentioned A rotation step of rotating the target is included.

A third aspect of the present invention relates to an X-ray generator, wherein the X-ray generator is an X-ray generator tube including an electron gun and a target that receives the electron beam emitted from the electron gun and generates X-rays. and a support structure for supporting the X-ray generating tube, and a deflector for deflecting the electron beam, the target having a circular shape and being made of a single metal or a single alloy, The support structure allows the X-ray generating tube to rotate at least the target about a rotation axis coinciding with the central axis of the electron gun while the deflector is fixed. support.

The figure which shows typically the structure of the X-ray generator of 1st Embodiment. 4 is a diagram schematically showing how an electron beam emitted from an electron gun collides with a target in the X-ray generator of the first embodiment; FIG. The figure which shows typically the adjustment method or usage method of the X-ray generator of a comparative example. 4A and 4B are diagrams schematically showing a method of adjusting or using the X-ray generator of the first embodiment; FIG. The figure which shows typically the structure of the X-ray generator of 2nd Embodiment. The figure which shows typically the structure of the X-ray generator of 3rd Embodiment. The figure which shows typically the structure of the X-ray generator of 4th Embodiment. The figure which shows typically the structure of the X-ray generator of 5th Embodiment. The figure which shows typically the structure of the X-ray generator of 6th Embodiment. The figure which shows typically the structure of the X-ray generator of one Embodiment. 1 is a diagram schematically showing the configuration of an X-ray imaging apparatus according to one embodiment; FIG.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. In addition, the following embodiments do not limit the invention according to the scope of claims. Although multiple features are described in the embodiments, not all of these multiple features are essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 schematically shows the configuration of an X-ray generator 1 according to the first embodiment. The X-ray generator 1 can be configured as a transmissive X-ray generator. The X-ray generator 1 has an X-ray generating tube XG. The X-ray generating tube XG can include an electron gun EG and a target 22 that receives an electron beam or electrons emitted from the electron gun EG to generate X-rays. In one example, the X-ray generating tube XG includes an insulating tube 10 having two open ends, an anode 20 closing one of the two open ends of the insulating tube 10, and an anode 20 closing the other of the two open ends of the insulating tube 10. and an occlusion member 30 that The anode 20 can include a target 22 , a target holding plate 21 holding the target 22 , and an electrode 23 supporting the target holding plate 21 and applying a potential to the target 22 via the target holding plate 21 . Closing member 30 may be configured to hold electron gun EG. The insulating tube 10, the anode 20 and the closing member 30 can form a container that defines an enclosed space. The closed space is maintained in a vacuum or at a high degree of vacuum.

The X-ray generator 1 can further include a tube support structure 60 that supports the X-ray generator tube XG, and a deflector 50 that deflects the electron beam emitted from the electron gun EG. The X-ray generator 1 may also comprise a deflector support structure 70 that supports the deflector 50 . Tube support structure 60 may support x-ray generating tube XG0 to allow at least target 22 to be rotated while deflector 50 is fixed. In another aspect, tube support structure 60 may support x-ray tube XG to allow x-ray tube XG to be rotated while deflector 50 is fixed. In yet another aspect, tube support structure 60 supports x-ray tube XG0 to allow x-ray tube XG to be rotated with deflector 50 supported by deflector support structure 70. sell. The tube support structure 60 and the deflector support structure 70 are structures that support the X-ray generating tube XG and the deflector 50 independently of each other. The rotation of the X-ray generating tube XG may be performed manually by, for example, an operator, or may be performed by a driving mechanism (not shown).

The deflector 50 can be arranged outside the X-ray generating tube XG. For example, the deflector 50 is configured such that a virtual plane VP3 intersecting the deflector 50 includes a virtual plane VP1 including the electron beam incident surface of the target 22 (surface facing the electron gun EG) and a tip surface of the electron gun EG (surface facing the target 22). ) and a virtual plane VP2 containing the . Virtual planes VP1, VP2, and VP3 can be defined as planes perpendicularly intersecting the central axis AX of the electron gun EG. The deflector 50 deflects the electron beam emitted from the electron gun EG by applying a magnetic field to the electron beam. The incident position of the electron beam on the target 22 can be adjusted or shifted by deflecting the electron beam with the deflector 50 .

The deflector 50 may be composed of a permanent magnet, may be composed of an electromagnet, or may be composed of a permanent magnet and an electromagnet. In one example, deflector 50 can include a first magnet and a second magnet. The first magnetic pole (for example, S pole) of the first magnet and the second magnetic pole (for example, N pole) of the second magnet can be arranged so as to face each other via the insulating tube 10 or the X-ray generating tube XG. . The deflector 50 may be composed of one magnet arranged so that the magnetic poles face the radial direction of the insulating tube 10 or the X-ray generating tube XG. Deflector 50 may be detachably supported by deflector support structure 70 . The deflector support structure 70 may include a drive mechanism for moving and/or rotating the deflector 50 or an adjustment mechanism for adjusting the position or orientation of the deflector 50 . By providing such a driving mechanism or adjusting mechanism, it is possible to adjust the magnetic field acting on the electron beam emitted from the X-ray generating tube XG.

The electrode 23 is electrically connected to the target 22 and applies an electric potential to the target 22 . The target 22 generates X-rays by bombarding the target 22 with electrons from the electron gun EG. The X-rays generated by the target 22 pass through the target holding plate 21 and are emitted to the outside of the X-ray generating tube XG. Anode 20 may be maintained at, for example, ground potential, but may be maintained at other potentials. Target 22 has a circular shape and may be composed of a single metal or single alloy. Single metals may contain small amounts of unintentional impurities. A single alloy is a metallic material in which a pure metal is mixed with one or more other elements. In another aspect, target 22 may have an axisymmetric structure and be composed of a single metal or single alloy. The target 22 is desirably made of a material with a high melting point, such as tungsten, tantalum, molybdenum, etc. These materials are advantageous for improving the efficiency of X-ray generation. The target holding plate 21 can be made of, for example, a material that easily transmits X-rays, such as beryllium or diamond.

FIG. 2 schematically shows how the electron beam EB emitted from the electron gun EG collides with the target 22 . Although the electron gun EG and the target 22 are shown in close proximity in FIG. 2, the electron gun EG and the target 22 may be spaced further apart. The electron beam EB emitted from the electron gun EG is incident on or collides with the target 22 after being deflected by the magnetic field generated by the deflector 50 . The amount by which the electron beam EB is deflected, in other words, the incident position of the electron beam EB on the target 22 can depend on the magnetic field generated by the deflector 50 and the acceleration voltage of the electron gun EG.

FIG. 3 schematically shows two states ST11 and ST12 of the X-ray generator in the comparative example. Both of the two states ST11 and ST12 show the target 22 viewed from the electron gun EG side. In state ST11, the electron beam emitted from the electron gun EG is deflected by the magnetic field generated by the deflector 50, and the electron beam is incident on the target 22 at the position P1. State ST12 is a state in which the deflector 50 is rotated with respect to the arrangement of the deflector 50 in state ST11. Therefore, the position P2 where the electron beam is incident on the target 22 in state ST12 is a position obtained by rotating the position P1 where the electron beam is incident on the target 22 in state ST11 around the central axis AX. That is, in the comparative example, the position where the electron beam is incident on the target 22 is changed from the position P1 to the position P2 by rotating the deflector 50 . In the comparative example, this can extend the life of the target 22 or the X-ray generator 1 . However, changing the position where the electron beam is incident on the target 22 from the position P1 to the position P2 means that the position where the X-rays are emitted from the target 22, that is, the focal position of the X-rays in the X-ray inspection apparatus is changed. meant to be changed. Therefore, in the comparative example, it is necessary to adjust the position of the X-ray detector according to the change in the position of the electron beam incident on the target 22 due to the rotation of the deflector 50 .

FIG. 4 schematically shows two states ST21 and ST22 of the X-ray generator 1 in the first embodiment. Both of the two states ST21 and ST22 show the target 22 viewed from the electron gun EG side. In state ST21, the electron beam emitted from the electron gun EG is deflected by the magnetic field generated by the deflector 50, and the electron beam is incident on the target 22 at the position P1. In state ST22, the X-ray generating tube XG (target 22) is rotated with respect to the orientation of the X-ray generating tube XG (target 22) in state ST21, and the electron beam is incident on the target 22 at position P2. In this example, the rotation angle of the target 22 is 90 degrees, but this rotation angle can be set arbitrarily. For example, considering the deflection of the electron beam, the range of damage on the target 22 due to the incident electron beam, and the like, a rotation angle of 3 degrees or more is desirable. Considering the rotation accuracy and the change in the incident position of the electron beam, it is more desirable that the angle is 10 degrees or more. Here, reference numeral 25 is a virtual azimuth mark given to the target 22 . In the first embodiment, the X-ray generating tube XG (target 22) is rotated while the deflector 50 is fixed. Therefore, in the state ST21 and the state ST22, the electron beams are incident on mutually different positions P1 and P2 of the target 22, but the positions P1 and P2 viewed from the X-ray detector, that is, the space where the X-ray generator 1 is arranged The positions P1 and P2 in are equal to each other. As a result, the service life of the target 22 or the X-ray generator 1 can be extended without changing the positions P1 and P2 in the space where the X-ray generator 1 is arranged, that is, the focal position.

As is clear from the above description, the method for adjusting the X-ray generator 1 of the embodiment includes a rotating step of rotating the X-ray generating tube XG while the deflector 50 is fixed. The rotation process can be performed according to the usage amount of the X-ray generator 1 . The usage amount can be, for example, at least one of the usage time of the X-ray generator 1, the amount of power applied to the electrode 23, or the cumulative value of the X-rays generated by the X-ray generator 1. FIG. Alternatively, the rotating step can be performed according to changes in X-rays generated by the X-ray generator 1 . For example, the rotation process is executed when the intensity of the X-rays generated by the X-ray generator 1 falls below a predetermined percentage of the intensity of the X-rays generated by the X-ray generator 1 immediately after execution of the last rotation process. can do.

The tube support structure 60 can support the X-ray generating tube XG so as to allow the X-ray generating tube XG to be pivoted about a pivot axis coinciding with the central axis AX of the electron gun EG. A central axis AX of the electron gun EG can be arranged to pass through the center of the target 22 . When the electron beam EB is not deflected by the deflector 50 , the electron beam EB can enter the center of the target 22 .

FIG. 5 schematically shows the configuration of the X-ray generator 1 of the second embodiment. Matters not mentioned in the X-ray generator 1 of the second embodiment can follow the first embodiment. In the second embodiment, the tube support structure 60 includes a housing portion 80 surrounding the X-ray generating tube XG. The housing part 80 can support the X-ray generating tube XG so as to allow the X-ray generating tube XG to be rotated while the deflector 50 is fixed. The space between the X-ray generating tube XG and the housing portion 80 can be filled or arranged with an insulating fluid (for example, insulating oil). The X-ray generator 1 may include an O-ring 82 , and the X-ray generating tube XG and the housing section 80 may have sealing surfaces facing each other via the O-ring 82 .

The housing portion 80 may include a seal portion 81 . The seal portion 81 may include a first surface 231 and a second surface 232 opposite to each other on the outer circumference of the electrode 23 of the anode 20 and a recess covering the end surface 233 of the outer circumference. O-ring 82 may be placed in contact with end face 233 or in a recess provided in end face 233 . A deflector support structure 70 that supports the deflector 50 may be connected to the receiving portion 80 .

FIG. 6 schematically shows the configuration of the X-ray generator 1 of the third embodiment. Matters not mentioned in the X-ray generator 1 of the third embodiment can follow the first or second embodiment. In the third embodiment, through holes 24 may be provided in the electrodes 23 . An O-ring 82 may be arranged between the upper surface of the housing portion 80 and the lower surface of the electrode 23 . The electrode 23 (anode 20 ) can be fixed to the housing portion 80 by a screw 83 passing through the through hole 24 . The through-hole 24 can be configured as an elongated hole, for example, to allow pivoting of the X-ray generating tube XG relative to the tube support structure 60 . When the screw 83 is loosened to rotate the X-ray generating tube XG, the torque can be controlled so that the sealing by the O-ring 82 is not lost. Alternatively, the rotation angle of the screw 83 can be limited within a predetermined angle so that the seal by the O-ring 82 is not lost when the screw 83 is loosened to rotate the X-ray generating tube XG.

FIG. 7 schematically shows the configuration of the X-ray generator 1 of the fourth embodiment. Matters not mentioned in the X-ray generator 1 of the fourth embodiment can follow the third embodiment. In the fourth embodiment, a regulation member 84 that regulates the position of the electrode 23 may be provided. The restricting member 84 can have, for example, a ring shape. A through hole 85 may be provided in the regulating member 84 . An O-ring 82 may be arranged between the upper surface of the housing portion 80 and the lower surface of the electrode 23 . The restricting member 84 can be fixed to the accommodating portion 80 by pressing the electrode 23 against the O-ring 82 with a screw 83 passing through the through hole 85 . The through hole 85 can be configured as an elongated hole, for example, to allow pivoting of the X-ray generating tube XG with respect to the tube support structure 60 .

FIG. 8 schematically shows the configuration of the X-ray generator 1 of the fifth embodiment. Matters not mentioned in the X-ray generator 1 of the fifth embodiment can follow the first to fourth embodiments. The X-ray generator 1 can have a mark 93 that indicates the rotation angle of the X-ray generator tube XG with respect to the tube support structure 60 . The X-ray generator 1 may include an engaging portion 91 that engages with a jig (not shown) for rotating the X-ray generating tube XG. The operator can rotate the X-ray generating tube XG by engaging a jig with the engaging portion 91 and operating the jig.

FIG. 9 schematically shows the configuration of the X-ray generator 1 of the sixth embodiment. Matters not mentioned in the X-ray generator 1 of the sixth embodiment can follow the first to fourth embodiments. The X-ray generator 1 can have a mark 93 that indicates the rotation angle of the X-ray generator tube XG with respect to the tube support structure 60 . The X-ray generator 1 may include an engaging portion 95 that engages with a jig (not shown) for rotating the X-ray generating tube XG. The operator can rotate the X-ray generating tube XG by engaging a jig with the engaging portion 95 and operating the jig.

FIG. 10 shows the configuration of the X-ray generator 1 of one embodiment. The X-ray generator 1 can include a booster circuit 110 and a drive circuit 120 in addition to the X-ray generator tube XG described above. The booster circuit 110 can generate a boosted voltage by boosting an externally supplied voltage and supply the boosted voltage to the drive circuit 120 . The drive circuit 120 can drive the X-ray generating tube XG based on the boosted voltage supplied from the booster circuit 110 . The X-ray generating tube XG, the booster circuit 110 and the drive circuit 120 are housed in the housing portion 80, and the space inside the housing portion 80 can be filled with insulating fluid.

FIG. 11 shows the configuration of an X-ray imaging apparatus 200 according to one embodiment. The X-ray imaging apparatus 200 can include an X-ray generator 1 and an X-ray detector 240 that detects X-rays XR emitted from the X-ray generator 1 and transmitted through an object 230 . X-ray detection device 240 may further comprise control device 210 and display device 220 . X-ray detection device 240 may include an X-ray detector 242 and a signal processor 244 . The controller 210 can control the X-ray generator 1 and the X-ray detector 240 . The X-ray detector 242 can detect or image X-rays XR emitted from the X-ray generator 1 and transmitted through the object 230 . Signal processor 244 may process signals output from X-ray detector 242 and provide processed signals to controller 210 . The control device 210 causes the display device 220 to display an image based on the signal supplied from the signal processing section 244 . The control device 210 determines whether it is necessary to perform the rotation process based on the usage amount of the X-ray generator 1 and/or changes in the X-rays generated by the X-ray generator 1, and determines whether it is necessary to perform the rotation process. When the determination is made, the display device 220 may be used to prompt the operator to perform the rotation process.

As described above, when the focal position of the X-ray emitted from the X-ray generator 1 (the incident position of the electron beam) is changed, the X-ray detector 242 or the X-ray detector 240 is aligned accordingly. There is a need. According to the X-ray generator 1 according to each of the above embodiments, the lifetime of the target or the X-ray generating tube can be extended without changing the focal position, so such alignment is unnecessary.

1: X-ray generator, EG: electron gun, 10: electron gun, 20: anode, 21: target holding plate, 22: target, 23: electrode, 30: closing member, 50: deflector, 60: tube support structure , 70: deflector support structure, AX: central axis, EB: electron beam, 80: accommodation unit

Claims (20)

an X-ray generating tube including an electron gun and a target for receiving an electron beam emitted from the electron gun to generate X-rays; a support structure for supporting the X-ray generating tube; and a deflector for deflecting the electron beam. an X-ray generator having
an X-ray detector that detects X-rays emitted from the X-ray generator;
a control device that controls the X-ray generator,
The support structure supports the X-ray generating tube so as to allow at least the target to be rotated while the deflector is fixed;
The control device determines whether or not the target needs to be rotated according to the amount of use of the X-ray generator and/or changes in X-rays generated by the X-ray generator. ,
An X-ray imaging apparatus characterized by: The support structure supports the X-ray tube so as to allow the X-ray tube to be rotated while the deflector is fixed.
The X-ray imaging apparatus according to claim 1, characterized in that: The support structure supports the X-ray generation tube so as to allow the X-ray generation tube to be rotated around a rotation axis coinciding with the central axis of the electron gun.
The X-ray imaging apparatus according to claim 1 , characterized in that: A central axis of the electron gun passes through the center of the target,
4. The X-ray imaging apparatus according to claim 3, characterized in that: the electron beam is incident on the center of the target when the electron beam is not deflected by the deflector;
The X-ray imaging apparatus according to claim 1 , characterized in that: the support structure includes a housing portion surrounding the X-ray generating tube;
The accommodating portion supports the X-ray generating tube so as to allow the X-ray generating tube to be rotated while the deflector is fixed.
The X-ray imaging apparatus according to claim 1 , characterized in that: an insulating fluid is disposed in a space between the X-ray generating tube and the housing;
7. The X-ray imaging apparatus according to claim 6, characterized by: further comprising an O-ring,
The X-ray generating tube and the housing have sealing surfaces facing each other via the O-ring.
8. The X-ray imaging apparatus according to claim 7, characterized by: the deflector includes a first magnet and a second magnet that are arranged to face each other through the accommodating portion;
7. The X-ray imaging apparatus according to claim 6 , characterized by: the X-ray generating tube has a mark indicating a rotation angle of the X-ray generating tube with respect to the support structure;
The X-ray imaging apparatus according to any one of claims 1 to 9, characterized by: an X-ray generating tube including an electron gun and a target for receiving an electron beam emitted from the electron gun to generate X-rays; a support structure for supporting the X-ray generating tube; and a deflector for deflecting the electron beam. A method for adjusting an X-ray generator comprising:
a rotating step of rotating at least the target while the deflector is fixed in accordance with the amount of use of the X-ray generator and/or changes in the X-rays generated by the X-ray generator; ,
A method for adjusting an X-ray generator, characterized by: In the rotating step, the X-ray generating tube is rotated while the deflector is fixed.
The method for adjusting an X-ray generator according to claim 11, characterized in that: In the rotating step, the X-ray generating tube is rotated around a rotation axis that coincides with the central axis of the electron gun.
The method for adjusting an X-ray generator according to claim 11 , characterized in that: A central axis of the electron gun passes through the center of the target,
14. The method for adjusting an X-ray generator according to claim 13, wherein: the electron beam is incident on the center of the target when the electron beam is not deflected by the deflector;
The method for adjusting an X-ray generator according to claim 11 , characterized in that: the support structure includes a housing portion surrounding the X-ray generating tube;
In the rotating step, the X-ray generating tube is rotated while the deflector and the accommodating portion are fixed.
The method for adjusting an X-ray generator according to any one of claims 11 to 15, characterized in that: the deflector includes a first magnet and a second magnet that are arranged to face each other through the accommodating portion;
17. The method for adjusting an X-ray generator according to claim 16, wherein: an X-ray generating tube including an electron gun and a target that receives electron beams emitted from the electron gun and generates X-rays;
a support structure for supporting the X-ray generating tube;
a deflector that deflects the electron beam,
The target has a circular shape and is composed of a single metal or a single alloy,
The support structure allows the X-ray generating tube to rotate at least the target about a rotation axis coinciding with the central axis of the electron gun while the deflector is fixed. in favor of
An X-ray generator characterized by: the center axis of the electron gun is arranged to pass through the center of the target;
19. The X-ray generator according to claim 18, characterized by: When the electron beam is not deflected by the deflector, the electron beam is incident on the center of the target.
19. The X-ray generator according to claim 18, characterized by:

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